Reorder LLEventDetail::listenerNameForCoro[Impl]() decls for Xcode 6.

indra/llcommon/lleventcoro.h

@@ -102,6 +102,9 @@ LLVoidListener<LISTENER> voidlistener(const LISTENER& listener)
 
 namespace LLEventDetail
 {
+    /// Implementation for listenerNameForCoro(), see below
+    LL_COMMON_API std::string listenerNameForCoroImpl(const void* self_id);
+
     /**
      * waitForEventOn() permits a coroutine to temporarily listen on an
      * LLEventPump any number of times. We don't really want to have to ask
@@ -129,9 +132,6 @@ namespace LLEventDetail
         return listenerNameForCoroImpl(self.get_id());
     }
 
-    /// Implementation for listenerNameForCoro()
-    LL_COMMON_API std::string listenerNameForCoroImpl(const void* self_id);
-
     /**
      * Implement behavior described for postAndWait()'s @a replyPumpNamePath
      * parameter: